aff02b62ccc390a6d000f355063f39f59c701bc2
1 /**
2 * collectd - src/zfs_arc.c
3 * Copyright (C) 2009 Anthony Dewhurst
4 * Copyright (C) 2012 Aurelien Rougemont
5 * Copyright (C) 2013 Xin Li
6 * Copyright (C) 2014 Marc Fournier
7 * Copyright (C) 2014 Wilfried Goesgens
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; only version 2 of the License is applicable.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 * Authors:
23 * Anthony Dewhurst <dewhurst at gmail>
24 * Aurelien Rougemont <beorn at gandi.net>
25 * Xin Li <delphij at FreeBSD.org>
26 * Marc Fournier <marc.fournier at camptocamp.com>
27 * Wilfried Goesgens <dothebart at citadel.org>
28 **/
30 #include "collectd.h"
32 #include "common.h"
33 #include "plugin.h"
35 /*
36 * Global variables
37 */
39 #if defined(KERNEL_LINUX)
40 #include "utils_llist.h"
41 #define ZOL_ARCSTATS_FILE "/proc/spl/kstat/zfs/arcstats"
43 typedef llist_t kstat_t;
45 static int put_zfs_value(kstat_t *ksp, char const *k, value_t v) {
46 llentry_t *e;
47 char *k_copy;
48 value_t *v_copy;
50 k_copy = strdup(k);
51 if (k_copy == NULL)
52 return ENOMEM;
54 v_copy = malloc(sizeof(*v_copy));
55 if (v_copy == NULL) {
56 sfree(k_copy);
57 return ENOMEM;
58 }
59 *v_copy = v;
61 e = llentry_create(k_copy, v_copy);
62 if (e == NULL) {
63 sfree(v_copy);
64 sfree(k_copy);
65 return ENOMEM;
66 }
68 llist_append(ksp, e);
69 return 0;
70 }
72 static long long get_zfs_value(kstat_t *ksp, const char *key) {
73 llentry_t *e;
74 value_t *v;
76 e = llist_search(ksp, key);
77 if (e == NULL) {
78 return (-1);
79 }
81 v = e->value;
82 return ((long long)v->derive);
83 }
85 static void free_zfs_values(kstat_t *ksp) {
86 if (ksp == NULL)
87 return;
89 for (llentry_t *e = llist_head(ksp); e != NULL; e = e->next) {
90 sfree(e->key);
91 sfree(e->value);
92 }
94 llist_destroy(ksp);
95 }
97 #elif defined(KERNEL_SOLARIS)
98 extern kstat_ctl_t *kc;
100 static long long get_zfs_value(kstat_t *ksp, char *name) {
102 return (get_kstat_value(ksp, name));
103 }
104 #elif defined(KERNEL_FREEBSD)
105 #include <sys/sysctl.h>
106 #include <sys/types.h>
108 const char zfs_arcstat[] = "kstat.zfs.misc.arcstats.";
110 #if !defined(kstat_t)
111 typedef void kstat_t;
112 #endif
114 static long long get_zfs_value(kstat_t *dummy __attribute__((unused)),
115 char const *name) {
116 char buffer[256];
117 long long value;
118 size_t valuelen = sizeof(value);
119 int rv;
121 ssnprintf(buffer, sizeof(buffer), "%s%s", zfs_arcstat, name);
122 rv = sysctlbyname(buffer, (void *)&value, &valuelen,
123 /* new value = */ NULL, /* new length = */ (size_t)0);
124 if (rv == 0)
125 return (value);
127 return (-1);
128 }
129 #endif
131 static void za_submit(const char *type, const char *type_instance,
132 value_t *values, size_t values_len) {
133 value_list_t vl = VALUE_LIST_INIT;
135 vl.values = values;
136 vl.values_len = values_len;
138 sstrncpy(vl.plugin, "zfs_arc", sizeof(vl.plugin));
139 sstrncpy(vl.type, type, sizeof(vl.type));
140 sstrncpy(vl.type_instance, type_instance, sizeof(vl.type_instance));
142 plugin_dispatch_values(&vl);
143 }
145 static void za_submit_gauge(const char *type, const char *type_instance,
146 gauge_t value) {
147 za_submit(type, type_instance, &(value_t){.gauge = value}, 1);
148 }
150 static int za_read_derive(kstat_t *ksp, const char *kstat_value,
151 const char *type, const char *type_instance) {
152 long long tmp = get_zfs_value(ksp, (char *)kstat_value);
153 if (tmp == -1LL) {
154 DEBUG("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
155 return (-1);
156 }
158 za_submit(type, type_instance, &(value_t){.derive = (derive_t)tmp},
159 /* values_num = */ 1);
160 return (0);
161 }
163 static int za_read_gauge(kstat_t *ksp, const char *kstat_value,
164 const char *type, const char *type_instance) {
165 long long tmp = get_zfs_value(ksp, (char *)kstat_value);
166 if (tmp == -1LL) {
167 DEBUG("zfs_arc plugin: Reading kstat value \"%s\" failed.", kstat_value);
168 return (-1);
169 }
171 za_submit(type, type_instance, &(value_t){.gauge = (gauge_t)tmp},
172 /* values_num = */ 1);
173 return (0);
174 }
176 static void za_submit_ratio(const char *type_instance, gauge_t hits,
177 gauge_t misses) {
178 gauge_t ratio = NAN;
180 if (!isfinite(hits) || (hits < 0.0))
181 hits = 0.0;
182 if (!isfinite(misses) || (misses < 0.0))
183 misses = 0.0;
185 if ((hits != 0.0) || (misses != 0.0))
186 ratio = hits / (hits + misses);
188 za_submit_gauge("cache_ratio", type_instance, ratio);
189 }
191 static int za_read(void) {
192 gauge_t arc_hits, arc_misses, l2_hits, l2_misses;
193 kstat_t *ksp = NULL;
195 #if defined(KERNEL_LINUX)
196 FILE *fh;
197 char buffer[1024];
199 fh = fopen(ZOL_ARCSTATS_FILE, "r");
200 if (fh == NULL) {
201 char errbuf[1024];
202 ERROR("zfs_arc plugin: Opening \"%s\" failed: %s", ZOL_ARCSTATS_FILE,
203 sstrerror(errno, errbuf, sizeof(errbuf)));
204 return (-1);
205 }
207 ksp = llist_create();
208 if (ksp == NULL) {
209 ERROR("zfs_arc plugin: `llist_create' failed.");
210 fclose(fh);
211 return (-1);
212 }
214 // Ignore the first two lines because they contain information about
215 // the rest of the file.
216 // See kstat_seq_show_headers module/spl/spl-kstat.c of the spl kernel
217 // module.
218 if (fgets(buffer, sizeof(buffer), fh) == NULL) {
219 ERROR("zfs_arc plugin: \"%s\" does not contain a single line.", ZOL_ARCSTATS_FILE);
220 fclose(fh);
221 return (-1);
222 }
223 if (fgets(buffer, sizeof(buffer), fh) == NULL) {
224 ERROR("zfs_arc plugin: \"%s\" does not contain at least two lines.", ZOL_ARCSTATS_FILE);
225 fclose(fh);
226 return (-1);
227 }
229 while (fgets(buffer, sizeof(buffer), fh) != NULL) {
230 char *fields[3];
231 value_t v;
232 int status;
234 status = strsplit(buffer, fields, STATIC_ARRAY_SIZE(fields));
235 if (status != 3)
236 continue;
238 status = parse_value(fields[2], &v, DS_TYPE_DERIVE);
239 if (status != 0)
240 continue;
242 put_zfs_value(ksp, fields[0], v);
243 }
245 fclose(fh);
247 #elif defined(KERNEL_SOLARIS)
248 get_kstat(&ksp, "zfs", 0, "arcstats");
249 if (ksp == NULL) {
250 ERROR("zfs_arc plugin: Cannot find zfs:0:arcstats kstat.");
251 return (-1);
252 }
253 #endif
255 /* Sizes */
256 za_read_gauge(ksp, "anon_size", "cache_size", "anon_size");
257 za_read_gauge(ksp, "c", "cache_size", "c");
258 za_read_gauge(ksp, "c_max", "cache_size", "c_max");
259 za_read_gauge(ksp, "c_min", "cache_size", "c_min");
260 za_read_gauge(ksp, "hdr_size", "cache_size", "hdr_size");
261 za_read_gauge(ksp, "metadata_size", "cache_size", "metadata_size");
262 za_read_gauge(ksp, "mfu_ghost_size", "cache_size", "mfu_ghost_size");
263 za_read_gauge(ksp, "mfu_size", "cache_size", "mfu_size");
264 za_read_gauge(ksp, "mru_ghost_size", "cache_size", "mru_ghost_size");
265 za_read_gauge(ksp, "mru_size", "cache_size", "mru_size");
266 za_read_gauge(ksp, "other_size", "cache_size", "other_size");
267 za_read_gauge(ksp, "p", "cache_size", "p");
268 za_read_gauge(ksp, "size", "cache_size", "arc");
270 /* The "l2_size" value has disappeared from Solaris some time in
271 * early 2013, and has only reappeared recently in Solaris 11.2.
272 * Stop trying if we ever fail to read it, so we don't spam the log.
273 */
274 static int l2_size_avail = 1;
275 if (l2_size_avail && za_read_gauge(ksp, "l2_size", "cache_size", "L2") != 0)
276 l2_size_avail = 0;
278 /* Operations */
279 za_read_derive(ksp, "deleted", "cache_operation", "deleted");
280 #if defined(KERNEL_FREEBSD)
281 za_read_derive(ksp, "allocated", "cache_operation", "allocated");
282 #endif
284 /* Issue indicators */
285 za_read_derive(ksp, "mutex_miss", "mutex_operations", "miss");
286 za_read_derive(ksp, "hash_collisions", "hash_collisions", "");
287 za_read_derive(ksp, "memory_throttle_count", "memory_throttle_count", "");
289 /* Evictions */
290 za_read_derive(ksp, "evict_l2_cached", "cache_eviction", "cached");
291 za_read_derive(ksp, "evict_l2_eligible", "cache_eviction", "eligible");
292 za_read_derive(ksp, "evict_l2_ineligible", "cache_eviction", "ineligible");
294 /* Hits / misses */
295 za_read_derive(ksp, "demand_data_hits", "cache_result", "demand_data-hit");
296 za_read_derive(ksp, "demand_metadata_hits", "cache_result",
297 "demand_metadata-hit");
298 za_read_derive(ksp, "prefetch_data_hits", "cache_result",
299 "prefetch_data-hit");
300 za_read_derive(ksp, "prefetch_metadata_hits", "cache_result",
301 "prefetch_metadata-hit");
302 za_read_derive(ksp, "demand_data_misses", "cache_result", "demand_data-miss");
303 za_read_derive(ksp, "demand_metadata_misses", "cache_result",
304 "demand_metadata-miss");
305 za_read_derive(ksp, "prefetch_data_misses", "cache_result",
306 "prefetch_data-miss");
307 za_read_derive(ksp, "prefetch_metadata_misses", "cache_result",
308 "prefetch_metadata-miss");
309 za_read_derive(ksp, "mfu_hits", "cache_result", "mfu-hit");
310 za_read_derive(ksp, "mfu_ghost_hits", "cache_result", "mfu_ghost-hit");
311 za_read_derive(ksp, "mru_hits", "cache_result", "mru-hit");
312 za_read_derive(ksp, "mru_ghost_hits", "cache_result", "mru_ghost-hit");
314 /* Ratios */
315 arc_hits = (gauge_t)get_zfs_value(ksp, "hits");
316 arc_misses = (gauge_t)get_zfs_value(ksp, "misses");
317 l2_hits = (gauge_t)get_zfs_value(ksp, "l2_hits");
318 l2_misses = (gauge_t)get_zfs_value(ksp, "l2_misses");
320 za_submit_ratio("arc", arc_hits, arc_misses);
321 za_submit_ratio("L2", l2_hits, l2_misses);
323 /* I/O */
324 value_t l2_io[] = {
325 {.derive = (derive_t)get_zfs_value(ksp, "l2_read_bytes")},
326 {.derive = (derive_t)get_zfs_value(ksp, "l2_write_bytes")},
327 };
328 za_submit("io_octets", "L2", l2_io, STATIC_ARRAY_SIZE(l2_io));
330 #if defined(KERNEL_LINUX)
331 free_zfs_values(ksp);
332 #endif
334 return (0);
335 } /* int za_read */
337 static int za_init(void) /* {{{ */
338 {
339 #if defined(KERNEL_SOLARIS)
340 /* kstats chain already opened by update_kstat (using *kc), verify everything
341 * went fine. */
342 if (kc == NULL) {
343 ERROR("zfs_arc plugin: kstat chain control structure not available.");
344 return (-1);
345 }
346 #endif
348 return (0);
349 } /* }}} int za_init */
351 void module_register(void) {
352 plugin_register_init("zfs_arc", za_init);
353 plugin_register_read("zfs_arc", za_read);
354 } /* void module_register */
356 /* vmi: set sw=8 noexpandtab fdm=marker : */